1. Field of the Invention
The invention relates to a flip-up cover mechanism, and more particularly to a flip-up cover mechanism with secure closing and easy lifting effects.
2. Description of the Related Art
A cover mechanism is often provided on a sight, protecting optical components therein.
Referring to FIG. 1A and FIG. 1B, a conventional flip-up cover mechanism 1 is provided on a sight S, protecting optical components therein.
As shown in FIGS. 1A, 1B, and 3, the flip-up cover mechanism 1 comprises an annular body 10, a cover 20, a torsion spring 30, and a pivot 40.
As shown in FIG. 1A and FIG. 1B, the annular body 10 is connected to an end (such as an objective lens tube) of the sight S. As shown in FIG. 2, the annular body 10 comprises a first flange 11.
As shown in FIG. 1A and FIG. 1B, the cover 20 is rotatably connected to the annular body 10. Additionally, as shown in FIG. 2, the cover 20 comprises a second flange 21.
As shown in FIG. 1A and FIG. 1B, the torsion spring 30 is connected between the annular body 10 and the cover 20, and the pivot 40 is fit in the annular body 10, cover 20, and torsion spring 30.
As shown in FIG. 1A and FIG. 2, when the cover 20 is closed in relation to the annular body 10, the second flange 21 of the cover 20 abuts and is engaged with the first flange 11 of the annular body 10 and the torsion spring 30 is twisted. In another aspect, an operator can push an outer edge of the cover 20, lifting the cover 20 from the annular body 10. At this point, the second flange 21 of the cover 20 and the first flange 11 of the annular body 10 are elastically deformed, and the second flange 21 then disengages from the first flange 11. As shown in FIG. 1B, after the second flange 21 is completely separated from the first flange 11, the cover 20 is lifted by restoring resilience provided by the torsion spring 30.
Accordingly, as the cover 20 is closed in relation to the annular body 10 by engagement between the second flange 21 and the first flange 11, a secure closing effect between the cover 20 and the annular body 10 depends on the quantity of interference between the second flange 21 and the first flange 11. Specifically, the greater the quantity of interference between the second flange 21 and the first flange 11, the better the secure closing effect between the cover 20 and the annular body 10. Nevertheless, ease of a lifting effect between the cover 20 and the annular body 10 also depends on the quantity of interference between the second flange 21 and the first flange 11. Specifically, the greater the quantity of interference between the second flange 21 and the first flange 11, the lesser the ease of the lifting effect between the cover 20 and the annular body 10 (i.e. the higher the force required for the operator to push the outer edge of the cover 20). Accordingly, the secure closing effect between the cover 20 and the annular body 10 is contrary to the ease of the lifting effect therebetween. However, to obtain balance between the secure closing effect and the ease of the lifting effect and manufacturing simplicity, the secure closing effect is primarily considered, causing inconvenient lifting operation between the cover 20 and the annular body 10 for users. Moreover, during lifting and closing operations between the cover 20 and the annular body 10, the second flange 21 of the cover 20 and the first flange 11 of the annular body 10 are subjected to frictional wear which is not dependent upon the quantity of interference between the second flange 21 and the first flange 11. Thus, after long-term operation, the secure closing effect between the cover 20 and the annular body 10 is tremendously reduced.